The digestive tract is a major component of the gastrointestinal system. Essentially, it is a tube about five meters in length of variable cross-sectional areas running from mouth to anus that includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine, which includes the colon, also known as the bowel. In the digestive tract, food is propelled by muscular contractions through its different regions. These contractions are referred to as peristalsis. Eventually, unabsorbed food residues are moved to the end of the tract and are eliminated from the body in the form of solids, semi-solids or liquids.
As used herein the term “digestive tract” includes, but is not limited to, the mouth, pharynx, esophagus, stomach, small intestine and large intestine. Also, as used herein, the terms “food residue” and “residue” include any composition of matter resulting from digested food and which has not been absorbed by the body's digestive system, including, but not limited to, any solid, semi-solid or liquid matter in the digestive tract. Such food residue includes, but is not limited to, any solid, semi-solid or liquid stool matter.
A digestive tract substantially free of food residue may be desirable, or even necessary, for a variety of medical reasons. For example, it is often preferable for an individual to undergo surgery with an empty stomach, or with a stomach containing little or no solid matter, because anesthesia or medication given to the patient prior to, during, or after surgery may cause the patient to vomit. Vomiting may pose a health danger if solid particles from the vomit are aspirated.
A substantially or completely residue-free digestive tract may also be desirable or necessary for surgery on any part of the gastrointestinal system, including, for example, surgery on the colon, abdomen, esophagus, stomach, duodenum, liver, pancreas, intestines, rectum and anus. Gastrointestinal surgery may be necessary to treat, for example, diseases such as colon cancer, rectal cancer, Crohn's disease, ulcerative colitis and diverticulitis.
If the digestive tract is not sufficiently cleansed in preparation for gastrointestinal surgery, there is risk of infection if, during the surgery, the digestive tract is perforated and food residue inadvertently contaminates the other organs in the individual's body. This is because the digestive tract (particularly the stomach and intestines) is full of a variety of ingested material. As this material makes its way from the stomach toward the anus, the character of the material changes from a watery, green liquid to a nearly solid stool. Further, as the digested food makes its way toward the anus, the amount of bacteria in this liquid material increases. Thus, a goal of removing food residue from the digestive tract is to decrease the amount of bacteria living therein.
With respect to surgery, a substantially or completely residue-free digestive tract can have numerous benefits. If the operation involves the removal of a segment of large intestine, for example, it is technically much easier to reconnect a clean intestine than it is to reconnect an intestine that contains substantial amounts of food residue. Also, a great source of potentially infectious bacteria in the human body is the large intestine. Eliminating these bacteria by removing the food residue from the digestive tract greatly decreases the chance of developing an infection postoperatively. Further, if the surgeon is trying to locate a mass present within the intestine, it is much easier to feel the mass from the outside if the intestine is at least substantially residue free.
Removal of stool matter from the digestive tract is also necessary to effectively screen for gastrointestinal abnormalities, including, but not limited to, cancer such as colon cancer. Since colon cancer is a highly treatable and often curable if detected early, screening tests for detecting premalignant polyps and colorectal cancers at stages early enough for complete removal are very important.
Current colon screening procedures include, for example, barium enema, sigmoidoscopy, fiberoptic endoscopy and virtual endoscopy. The double-contrast barium enema colon screening procedure uses x-ray imaging, which allows a view of the rectum and of the entire colon. Sigmoidoscopy and fiberoptic endoscopy procedures involve snaking a fiberoptic tube through regions of the rectum and colon (part of the large intestine) to view the walls of the intestine. During either procedure, the physician is able to remove polyps or other abnormalities. Finally, virtual endoscopy utilizes computer reformation of radiologic images to form images of the colon in two or three dimensions. Removing sufficient amounts of stool matter from the colon prior to a colon screening procedure is essential. For some screenings, the colon must be at least substantially free of food residue (e.g., stool matter) in order for the optical or video endoscope or x-ray to accurately image the intestine. Further, stool matter can physically block the progress of the endoscope within the colon, thus preventing the screening. With respect to virtual endoscopy, stool and colon lesions can be indistinguishable in computer tomography or other radiologic modality images. Thus, stool matter can prevent a physician's ability to distinguish pathology from retained fecal debris.
Generally, two procedures are used to remove stool matter from the digestive tract in preparation for surgery or a colon screening. These regimens include: (1) pharmaco-mechanical preparations and (2) antibiotic preparations. Pharmaco-mechanical preparations involve taking drugs that cause the expulsion of the digestive tract's contents in the form of stool and/or diarrhea. An example of such a preparation is a large volume preparation such as Golytely.™, which requires drinking large volumes to physically flush at least some food residue out of the gastrointestinal tract. Another example of such a preparation is a smaller volume preparation such as Fleet.™ Phospho-Soda or magnesium citrate, which are saline-cathartic agents that pull additional fluid from the body to physically flush at least some food residue out of the gastrointestinal tract. Other pharmaco-mechanical preparations include bisacodyl tablets, suppositories or enemas, which work by stimulating peristalsis, i.e., by acting on smooth muscle to cause contractions that physically push food residue out of the gastrointestinal tract.
One problem with some current pharmaco-mechanical preparation techniques is that they dehydrate the patient. Another problem is that some of the preparations can cause a chemical imbalance, and thus may not be safe for use by individuals with kidney disease or a known electrolyte disturbance, for example. Further, mechanical preparation techniques may be difficult to comply with, since they require consuming large volumes of liquid and abstinence from solid foods.
The antibiotic preparation is administered either orally or intravenously. Oral administration requires taking a non-absorbable antibiotic the evening before a medical procedure, such as gastrointestinal surgery. Frequently, however, these antibiotics cause such painful upset stomach or stomach cramps that the preparation is not completed. While intravenous administration of an antibiotic immediately prior to surgery may avoid the painful stomach cramping, many doctors choose not to use the intravenous method. The pharmaco-mechanical preparation and antibiotic preparation are typically used with a clear-liquid diet. Such a diet generally requires the intake of only clear liquids, e.g., clear juices, water and minerals, for a period of about 20- to 36-hours prior to a procedure. A clear liquid diet is used with most stool removal regimens because clear liquids are easily absorbed by the body, reduce stimulation of the digestive system, and leave no solid food residue in the digestive tract. A clear liquid diet may also be used alone to maintain the digestive tract at least substantially free of food residue for a short period of time. Examples of foods that may be consumed on a clear liquid diet are listed in Table 1. Table 2 lists an example of a 24-hour clear liquid diet.
TABLE 1Examples of Permissible Foods for Clear Liquid DietFood GroupsGroupRecommendAvoidMilk & milk productsnoneallVegetablesnoneallFruitsfruit juices without pulpnectars; allfresh, canned,and frozen fruitsBreads & grainsnoneallMeat or meatnoneallsubstitutesFats & oilsnoneallSweets & dessertsgelatin, fruit ice, Popsicleall otherswithout pulp, clear hard candyBeveragescoffee; tea; soft drinks; water;all otherslactose-free, low residuesupplements if approved byphysicianSoupsbouillon, consomméall othersfat free broth
TABLE 2Example of a 24-Hour Clear Liquid DietSample MenuBreakfastLunchDinnerstrained fruit juiceconsommé ¾ cupconsommé ¾ cup1 cupstrained fruit juicestrained fruit juicegelatin 1 cup1 cup1 cuphot tea with sugarfruit ice ½ cupfruit ice ½ cup& lemongelatin ½ cupgelatin ½ cuphot tea with sugar &hot tea with sugarlemon& lemon
The diet listed in Table 2 provides about 600 calories, 6 grams (g) of protein and about 209 g of carbohydrates. The diet also provides about 1,500 milligrams (mg) of sodium and 1,440 mg of potassium. The diet contains virtually no fat. Thus, a drawback of the clear liquid diet is that it does not adequately supply sufficient levels of calories and nutrients. Because traditional clear liquid diets provide almost no nutritional value, it is common for individuals to suffer from lightheadedness and drowsiness when adhering to such a diet, thus making it is difficult to perform daily, routine activities. At times, an individual on the clear liquid diet experiences such severe symptoms that a doctor prescribes medication such as metaclopramide, and other anti-nausea drugs. A discussion of clear liquid diets known in the art is contained in Appendix A of U.S. Provisional Application Ser. No. 60/240,569, which is herein incorporated by reference.
It is also known in the art for physicians to recommend a low-fiber, low-residue diet as part of the treatment for certain conditions such as diverticulitis, inflammatory conditions of the bowel, colitis and Chron's disease. A discussion of low fiber, low residue diets known in the art is contained in Appendix B of U.S. Provisional Application Ser. No. 60/240,569, which is herein incorporated by reference. Examples of foods that may be consumed by a patient on a low residue, low fiber diet are listed in Table 3. Table 4 lists an example of a 24-hour low fiber diet.
TABLE 3Examples of Permissible Foods for Low Fiber DietFood GroupsGroupRecommendAvoidMilk & milk products (2 orall milk productsLow Residue Diet only 2more cups daily)cups daily of all milkproductsVegetableslettuce; vegetable juice withoutvegetable juices with pulp,(3 or more servings daily)pulp; the following cookedraw vegetables exceptvegetables: yellow squashlettuce, cooked vegetables(without seeds), green beans,not on Recommended listwax beans, spinach, pumpkin,eggplant, potatoes, without skin,asparagus, beets, carrotsFruits (2 or more servingsfruit juices without pulp, cannedfruit-juices with pulp,daily)fruit except pineapple, ripecanned pineapple, freshbananas, melonsfruit except those onRecommend list, prunes,prune juice, dried fruit, jam,marmaladeStarches-Breads & grains (4bread and cereals made fromwhole-grain breads, cereals,or more servings daily)refined flours, pasta, white ricerice, pasta; bran cereal;oatmealMeat or meat substitutes (5meat, poultry, eggs, seafoodchunky peanut butter, nuts,or 6 oz daily)seeds, dried beans, driedpeasFats & oils (servings dependall oils, margarine, buttercoconuton caloric needs)Sweets & desserts (servingsall sweets and dessert, exceptdesserts containing nuts,depend on caloric needs)those on the “Avoid” listcoconutMiscellaneousall, except those on the “Avoid”popcorn, pickles,listhorseradish, relish
TABLE 4Example of a 24-Hour Low Fiber DietSample MenuBreakfastLunchDinnerorange juicefish or veal 3 ozchicken breast 3 oz½ cupmashed potatoes ½medium bakedcornflakes 1 cupcuppotato without skinpoached eggcooked green beans ½cooked carrots ½white toast 1 slicecupcupmargarine 1 tspwhite bread 1 slicewhite bread 1 slicejelly 1 Tbspmargarine 1 tspmargarine 1 tspskim milk 1 cupjelly 1 Tbspjelly 1 tbspcoffee ¾ cupapplesauce ½ cupcanned peaches ½sugar 1 tspcoffee ¾ cupcupnon-dairy creamersugar 1 tspskim milk ½ cupsalt/peppernon-dairy creamercoffee ¾ cupsalt/peppersugar 1 tspnon-dairy creamersalt/pepper
The diet listed above in Table 4 provides approximately 1,576 calories, 89 g of protein and 215 g of carbohydrates. The diet also provides 45 g of fat, about 2,817 mg of sodium and 3,510 mg of potassium. It also provides approximately 15 g of dietary fiber.
There is, therefore, a need for a nutritional diet which, when coordinated with a laxative regimen, effectively removes food residue from the digestive tract while providing the user with a sufficient level of calories and nutrition to conduct routine, daily activities. In addition, there is a need for a dietary regimen to be used in conjunction with a laxative regimen, while at the same time facilitating user compliance to the diet, since current cleansing techniques are often difficult or painful to complete, or require a high-degree of will power. The consequences of noncompliance can be great. For example, noncompliance can result in an ineffective colon screening or a post operative infection.
Additionally, there is a need for a nutritional dietary regimen which is readily useable and convenient, while also ensuring that the diet is exactly followed by the user. This is especially important for sick or incapacitated individuals incapable of acquiring or preparing specific food items.